The present invention relates in general to low power, high speed wireless data communications, and, more specifically, to providing high speed wireless communication links in structures such as motor vehicles with reduced interference, reduced human exposure, and low cost.
Due to the advancement of controls and the various electronic accessories being installed in motor vehicles, data transfer rates must be used which exceed the capacity of simple twisted wire (or coaxial cable) multiplex networks to carry. High data rate devices such as video cameras or radar sensors may be deployed at the exterior of a vehicle while the high speed data they create needs to be sent elsewhere in the vehicle for processing or display. As the number of electronic modules increases, the complexity and cost associated with the wire, connectors, and the routing of the wires becomes excessive. In addition, mechanical failures of wires in large wire bundles can be difficult to isolate and costly to repair. Fiber optic cables may be employed for high speed communication channels, but they result in high costs and may not be well suited to the harsh automotive environment.
Wireless technologies, such as Bluetooth and the IEEE standard 802.11 for wireless networks, can be used in vehicles but certain disadvantages have slowed their adoption. The radio-frequency (RF) radiation produced by a wireless transmitter in a vehicle can cause interference for and undesired interoperation with other systems in the same vehicle or in other nearby vehicles. The wireless receiver is susceptible to interference from other wireless devices as well as other man-made and natural interference such as lightning. Power output drivers for the transmitter must operate at sufficiently high power in order to overcome potential sources of interference. Furthermore, existing systems are omni-directional and radiate in substantially all directions into free space even though only a small portion of the radiated power is used by the intended receiver(s). The size of the output drivers that have been required to provide the necessary amount of power has resulted in high transceiver cost.